| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix out-of-bounds write in smb2_get_ea() EA alignment
smb2_get_ea() applies 4-byte alignment padding via memset() after
writing each EA entry. The bounds check on buf_free_len is performed
before the value memcpy, but the alignment memset fires unconditionally
afterward with no check on remaining space.
When the EA value exactly fills the remaining buffer (buf_free_len == 0
after value subtraction), the alignment memset writes 1-3 NUL bytes
past the buf_free_len boundary. In compound requests where the response
buffer is shared across commands, the first command (e.g., READ) can
consume most of the buffer, leaving a tight remainder for the QUERY_INFO
EA response. The alignment memset then overwrites past the physical
kvmalloc allocation into adjacent kernel heap memory.
Add a bounds check before the alignment memset to ensure buf_free_len
can accommodate the padding bytes.
This is the same bug pattern fixed by commit beef2634f81f ("ksmbd: fix
potencial OOB in get_file_all_info() for compound requests") and
commit fda9522ed6af ("ksmbd: fix OOB write in QUERY_INFO for compound
requests"), both of which added bounds checks before unconditional
writes in QUERY_INFO response handlers. |
| CloudPirates Open Source Helm Charts is a collection of Helm charts. Prior to commit fcf9302, a GitHub Actions workflow (pull-request.yaml) executes attacker-controlled code from fork pull requests in a privileged context, exposing repository secrets including Docker Hub credentials and tokens without requiring maintainer approval. This issue has been patched via commit fcf9302. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: use check_add_overflow() to prevent u16 DACL size overflow
set_posix_acl_entries_dacl() and set_ntacl_dacl() accumulate ACE sizes
in u16 variables. When a file has many POSIX ACL entries, the
accumulated size can wrap past 65535, causing the pointer arithmetic
(char *)pndace + *size to land within already-written ACEs. Subsequent
writes then overwrite earlier entries, and pndacl->size gets a
truncated value.
Use check_add_overflow() at each accumulation point to detect the
wrap before it corrupts the buffer, consistent with existing
check_mul_overflow() usage elsewhere in smbacl.c. |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix use-after-free of sbi in f2fs_compress_write_end_io()
In f2fs_compress_write_end_io(), dec_page_count(sbi, type) can bring
the F2FS_WB_CP_DATA counter to zero, unblocking
f2fs_wait_on_all_pages() in f2fs_put_super() on a concurrent unmount
CPU. The unmount path then proceeds to call
f2fs_destroy_page_array_cache(sbi), which destroys
sbi->page_array_slab via kmem_cache_destroy(), and eventually
kfree(sbi). Meanwhile, the bio completion callback is still executing:
when it reaches page_array_free(sbi, ...), it dereferences
sbi->page_array_slab — a destroyed slab cache — to call
kmem_cache_free(), causing a use-after-free.
This is the same class of bug as CVE-2026-23234 (which fixed the
equivalent race in f2fs_write_end_io() in data.c), but in the
compressed writeback completion path that was not covered by that fix.
Fix this by moving dec_page_count() to after page_array_free(), so
that all sbi accesses complete before the counter decrement that can
unblock unmount. For non-last folios (where atomic_dec_return on
cic->pending_pages is nonzero), dec_page_count is called immediately
before returning — page_array_free is not reached on this path, so
there is no post-decrement sbi access. For the last folio,
page_array_free runs while the F2FS_WB_CP_DATA counter is still
nonzero (this folio has not yet decremented it), keeping sbi alive,
and dec_page_count runs as the final operation. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: caiaq: take a reference on the USB device in create_card()
The caiaq driver stores a pointer to the parent USB device in
cdev->chip.dev but never takes a reference on it. The card's
private_free callback, snd_usb_caiaq_card_free(), can run
asynchronously via snd_card_free_when_closed() after the USB
device has already been disconnected and freed, so any access to
cdev->chip.dev in that path dereferences a freed usb_device.
On top of the refcounting issue, the current card_free implementation
calls usb_reset_device(cdev->chip.dev). A reset in a free callback
is inappropriate: the device is going away, the call takes the
device lock in a teardown context, and the reset races with the
disconnect path that the callback is already cleaning up after.
Take a reference on the USB device in create_card() with
usb_get_dev(), drop it with usb_put_dev() in the free callback,
and remove the usb_reset_device() call. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: ccp: Don't attempt to copy CSR to userspace if PSP command failed
When retrieving the PEK CSR, don't attempt to copy the blob to userspace
if the firmware command failed. If the failure was due to an invalid
length, i.e. the userspace buffer+length was too small, copying the number
of bytes _firmware_ requires will overflow the kernel-allocated buffer and
leak data to userspace.
BUG: KASAN: slab-out-of-bounds in instrument_copy_to_user ../include/linux/instrumented.h:129 [inline]
BUG: KASAN: slab-out-of-bounds in _inline_copy_to_user ../include/linux/uaccess.h:205 [inline]
BUG: KASAN: slab-out-of-bounds in _copy_to_user+0x66/0xa0 ../lib/usercopy.c:26
Read of size 2084 at addr ffff898144612e20 by task syz.9.219/21405
CPU: 14 UID: 0 PID: 21405 Comm: syz.9.219 Tainted: G U O 7.0.0-smp-DEV #28 PREEMPTLAZY
Tainted: [U]=USER, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.62.0-0 11/19/2025
Call Trace:
<TASK>
dump_stack_lvl+0xc5/0x110 ../lib/dump_stack.c:120
print_address_description ../mm/kasan/report.c:378 [inline]
print_report+0xbc/0x260 ../mm/kasan/report.c:482
kasan_report+0xa2/0xe0 ../mm/kasan/report.c:595
check_region_inline ../mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x264/0x2c0 ../mm/kasan/generic.c:200
instrument_copy_to_user ../include/linux/instrumented.h:129 [inline]
_inline_copy_to_user ../include/linux/uaccess.h:205 [inline]
_copy_to_user+0x66/0xa0 ../lib/usercopy.c:26
copy_to_user ../include/linux/uaccess.h:236 [inline]
sev_ioctl_do_pek_csr+0x31f/0x590 ../drivers/crypto/ccp/sev-dev.c:1872
sev_ioctl+0x3a4/0x490 ../drivers/crypto/ccp/sev-dev.c:2562
vfs_ioctl ../fs/ioctl.c:51 [inline]
__do_sys_ioctl ../fs/ioctl.c:597 [inline]
__se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:583
do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe0/0x800 ../arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
</TASK>
WARN if the driver says the command succeeded, but the firmware error code
says otherwise, as __sev_do_cmd_locked() is expected to return -EIO on any
firwmware error. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: ccp: Don't attempt to copy PDH cert to userspace if PSP command failed
When retrieving the PDH cert, don't attempt to copy the blobs to userspace
if the firmware command failed. If the failure was due to an invalid
length, i.e. the userspace buffer+length was too small, copying the number
of bytes _firmware_ requires will overflow the kernel-allocated buffer and
leak data to userspace.
BUG: KASAN: slab-out-of-bounds in instrument_copy_to_user ../include/linux/instrumented.h:129 [inline]
BUG: KASAN: slab-out-of-bounds in _inline_copy_to_user ../include/linux/uaccess.h:205 [inline]
BUG: KASAN: slab-out-of-bounds in _copy_to_user+0x66/0xa0 ../lib/usercopy.c:26
Read of size 2084 at addr ffff8885c4ab8aa0 by task syz.0.186/21033
CPU: 51 UID: 0 PID: 21033 Comm: syz.0.186 Tainted: G U O 7.0.0-smp-DEV #28 PREEMPTLAZY
Tainted: [U]=USER, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.84.12-0 11/17/2025
Call Trace:
<TASK>
dump_stack_lvl+0xc5/0x110 ../lib/dump_stack.c:120
print_address_description ../mm/kasan/report.c:378 [inline]
print_report+0xbc/0x260 ../mm/kasan/report.c:482
kasan_report+0xa2/0xe0 ../mm/kasan/report.c:595
check_region_inline ../mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x264/0x2c0 ../mm/kasan/generic.c:200
instrument_copy_to_user ../include/linux/instrumented.h:129 [inline]
_inline_copy_to_user ../include/linux/uaccess.h:205 [inline]
_copy_to_user+0x66/0xa0 ../lib/usercopy.c:26
copy_to_user ../include/linux/uaccess.h:236 [inline]
sev_ioctl_do_pdh_export+0x3d3/0x7c0 ../drivers/crypto/ccp/sev-dev.c:2347
sev_ioctl+0x2a2/0x490 ../drivers/crypto/ccp/sev-dev.c:2568
vfs_ioctl ../fs/ioctl.c:51 [inline]
__do_sys_ioctl ../fs/ioctl.c:597 [inline]
__se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:583
do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe0/0x800 ../arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
</TASK>
WARN if the driver says the command succeeded, but the firmware error code
says otherwise, as __sev_do_cmd_locked() is expected to return -EIO on any
firwmware error. |
| CloudPirates Open Source Helm Charts is a collection of Helm charts. Prior to commit fcf9302, a GitHub Actions workflow (generate-schema.yaml) exposes sensitive credentials (Personal Access Token and SSH signing key) to fork-controlled code due to unsafe checkout and credential handling practices. This issue has been patched via commit fcf9302. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: ccp: Don't attempt to copy ID to userspace if PSP command failed
When retrieving the ID for the CPU, don't attempt to copy the ID blob to
userspace if the firmware command failed. If the failure was due to an
invalid length, i.e. the userspace buffer+length was too small, copying
the number of bytes _firmware_ requires will overflow the kernel-allocated
buffer and leak data to userspace.
BUG: KASAN: slab-out-of-bounds in instrument_copy_to_user ../include/linux/instrumented.h:129 [inline]
BUG: KASAN: slab-out-of-bounds in _inline_copy_to_user ../include/linux/uaccess.h:205 [inline]
BUG: KASAN: slab-out-of-bounds in _copy_to_user+0x66/0xa0 ../lib/usercopy.c:26
Read of size 64 at addr ffff8881867f5960 by task syz.0.906/24388
CPU: 130 UID: 0 PID: 24388 Comm: syz.0.906 Tainted: G U O 7.0.0-smp-DEV #28 PREEMPTLAZY
Tainted: [U]=USER, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.62.0-0 11/19/2025
Call Trace:
<TASK>
dump_stack_lvl+0xc5/0x110 ../lib/dump_stack.c:120
print_address_description ../mm/kasan/report.c:378 [inline]
print_report+0xbc/0x260 ../mm/kasan/report.c:482
kasan_report+0xa2/0xe0 ../mm/kasan/report.c:595
check_region_inline ../mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x264/0x2c0 ../mm/kasan/generic.c:200
instrument_copy_to_user ../include/linux/instrumented.h:129 [inline]
_inline_copy_to_user ../include/linux/uaccess.h:205 [inline]
_copy_to_user+0x66/0xa0 ../lib/usercopy.c:26
copy_to_user ../include/linux/uaccess.h:236 [inline]
sev_ioctl_do_get_id2+0x361/0x490 ../drivers/crypto/ccp/sev-dev.c:2222
sev_ioctl+0x25f/0x490 ../drivers/crypto/ccp/sev-dev.c:2575
vfs_ioctl ../fs/ioctl.c:51 [inline]
__do_sys_ioctl ../fs/ioctl.c:597 [inline]
__se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:583
do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe0/0x800 ../arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
</TASK>
WARN if the driver says the command succeeded, but the firmware error code
says otherwise, as __sev_do_cmd_locked() is expected to return -EIO on any
firwmware error. |
| In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix missing validation of ticket length in non-XDR key preparsing
In rxrpc_preparse(), there are two paths for parsing key payloads: the
XDR path (for large payloads) and the non-XDR path (for payloads <= 28
bytes). While the XDR path (rxrpc_preparse_xdr_rxkad()) correctly
validates the ticket length against AFSTOKEN_RK_TIX_MAX, the non-XDR
path fails to do so.
This allows an unprivileged user to provide a very large ticket length.
When this key is later read via rxrpc_read(), the total
token size (toksize) calculation results in a value that exceeds
AFSTOKEN_LENGTH_MAX, triggering a WARN_ON().
[ 2001.302904] WARNING: CPU: 2 PID: 2108 at net/rxrpc/key.c:778 rxrpc_read+0x109/0x5c0 [rxrpc]
Fix this by adding a check in the non-XDR parsing path of rxrpc_preparse()
to ensure the ticket length does not exceed AFSTOKEN_RK_TIX_MAX,
bringing it into parity with the XDR parsing logic. |
| In the Linux kernel, the following vulnerability has been resolved:
fuse: reject oversized dirents in page cache
fuse_add_dirent_to_cache() computes a serialized dirent size from the
server-controlled namelen field and copies the dirent into a single
page-cache page. The existing logic only checks whether the dirent fits
in the remaining space of the current page and advances to a fresh page
if not. It never checks whether the dirent itself exceeds PAGE_SIZE.
As a result, a malicious FUSE server can return a dirent with
namelen=4095, producing a serialized record size of 4120 bytes. On 4 KiB
page systems this causes memcpy() to overflow the cache page by 24 bytes
into the following kernel page.
Reject dirents that cannot fit in a single page before copying them into
the readdir cache. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/kasan: fix double free for kasan pXds
kasan_free_pxd() assumes the page table is always struct page aligned.
But that's not always the case for all architectures. E.g. In case of
powerpc with 64K pagesize, PUD table (of size 4096) comes from slab cache
named pgtable-2^9. Hence instead of page_to_virt(pxd_page()) let's just
directly pass the start of the pxd table which is passed as the 1st
argument.
This fixes the below double free kasan issue seen with PMEM:
radix-mmu: Mapped 0x0000047d10000000-0x0000047f90000000 with 2.00 MiB pages
==================================================================
BUG: KASAN: double-free in kasan_remove_zero_shadow+0x9c4/0xa20
Free of addr c0000003c38e0000 by task ndctl/2164
CPU: 34 UID: 0 PID: 2164 Comm: ndctl Not tainted 6.19.0-rc1-00048-gea1013c15392 #157 VOLUNTARY
Hardware name: IBM,9080-HEX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_012) hv:phyp pSeries
Call Trace:
dump_stack_lvl+0x88/0xc4 (unreliable)
print_report+0x214/0x63c
kasan_report_invalid_free+0xe4/0x110
check_slab_allocation+0x100/0x150
kmem_cache_free+0x128/0x6e0
kasan_remove_zero_shadow+0x9c4/0xa20
memunmap_pages+0x2b8/0x5c0
devm_action_release+0x54/0x70
release_nodes+0xc8/0x1a0
devres_release_all+0xe0/0x140
device_unbind_cleanup+0x30/0x120
device_release_driver_internal+0x3e4/0x450
unbind_store+0xfc/0x110
drv_attr_store+0x78/0xb0
sysfs_kf_write+0x114/0x140
kernfs_fop_write_iter+0x264/0x3f0
vfs_write+0x3bc/0x7d0
ksys_write+0xa4/0x190
system_call_exception+0x190/0x480
system_call_vectored_common+0x15c/0x2ec
---- interrupt: 3000 at 0x7fff93b3d3f4
NIP: 00007fff93b3d3f4 LR: 00007fff93b3d3f4 CTR: 0000000000000000
REGS: c0000003f1b07e80 TRAP: 3000 Not tainted (6.19.0-rc1-00048-gea1013c15392)
MSR: 800000000280f033 <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> CR: 48888208 XER: 00000000
<...>
NIP [00007fff93b3d3f4] 0x7fff93b3d3f4
LR [00007fff93b3d3f4] 0x7fff93b3d3f4
---- interrupt: 3000
The buggy address belongs to the object at c0000003c38e0000
which belongs to the cache pgtable-2^9 of size 4096
The buggy address is located 0 bytes inside of
4096-byte region [c0000003c38e0000, c0000003c38e1000)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3c38c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:c0000003bfd63e01
flags: 0x63ffff800000040(head|node=6|zone=0|lastcpupid=0x7ffff)
page_type: f5(slab)
raw: 063ffff800000040 c000000140058980 5deadbeef0000122 0000000000000000
raw: 0000000000000000 0000000080200020 00000000f5000000 c0000003bfd63e01
head: 063ffff800000040 c000000140058980 5deadbeef0000122 0000000000000000
head: 0000000000000000 0000000080200020 00000000f5000000 c0000003bfd63e01
head: 063ffff800000002 c00c000000f0e301 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
[ 138.953636] [ T2164] Memory state around the buggy address:
[ 138.953643] [ T2164] c0000003c38dff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 138.953652] [ T2164] c0000003c38dff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 138.953661] [ T2164] >c0000003c38e0000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 138.953669] [ T2164] ^
[ 138.953675] [ T2164] c0000003c38e0080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 138.953684] [ T2164] c0000003c38e0100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 138.953692] [ T2164] ==================================================================
[ 138.953701] [ T2164] Disabling lock debugging due to kernel taint |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: ip6t_eui64: reject invalid MAC header for all packets
`eui64_mt6()` derives a modified EUI-64 from the Ethernet source address
and compares it with the low 64 bits of the IPv6 source address.
The existing guard only rejects an invalid MAC header when
`par->fragoff != 0`. For packets with `par->fragoff == 0`, `eui64_mt6()`
can still reach `eth_hdr(skb)` even when the MAC header is not valid.
Fix this by removing the `par->fragoff != 0` condition so that packets
with an invalid MAC header are rejected before accessing `eth_hdr(skb)`. |
| In the Linux kernel, the following vulnerability has been resolved:
net: sched: act_csum: validate nested VLAN headers
tcf_csum_act() walks nested VLAN headers directly from skb->data when an
skb still carries in-payload VLAN tags. The current code reads
vlan->h_vlan_encapsulated_proto and then pulls VLAN_HLEN bytes without
first ensuring that the full VLAN header is present in the linear area.
If only part of an inner VLAN header is linearized, accessing
h_vlan_encapsulated_proto reads past the linear area, and the following
skb_pull(VLAN_HLEN) may violate skb invariants.
Fix this by requiring pskb_may_pull(skb, VLAN_HLEN) before accessing and
pulling each nested VLAN header. If the header still is not fully
available, drop the packet through the existing error path. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_multiport: validate range encoding in checkentry
ports_match_v1() treats any non-zero pflags entry as the start of a
port range and unconditionally consumes the next ports[] element as
the range end.
The checkentry path currently validates protocol, flags and count, but
it does not validate the range encoding itself. As a result, malformed
rules can mark the last slot as a range start or place two range starts
back to back, leaving ports_match_v1() to step past the last valid
ports[] element while interpreting the rule.
Reject malformed multiport v1 rules in checkentry by validating that
each range start has a following element and that the following element
is not itself marked as another range start. |
| In the Linux kernel, the following vulnerability has been resolved:
rxrpc: only handle RESPONSE during service challenge
Only process RESPONSE packets while the service connection is still in
RXRPC_CONN_SERVICE_CHALLENGING. Check that state under state_lock before
running response verification and security initialization, then use a local
secured flag to decide whether to queue the secured-connection work after
the state transition. This keeps duplicate or late RESPONSE packets from
re-running the setup path and removes the unlocked post-transition state
test. |
| In the Linux kernel, the following vulnerability has been resolved:
af_unix: read UNIX_DIAG_VFS data under unix_state_lock
Exact UNIX diag lookups hold a reference to the socket, but not to
u->path. Meanwhile, unix_release_sock() clears u->path under
unix_state_lock() and drops the path reference after unlocking.
Read the inode and device numbers for UNIX_DIAG_VFS while holding
unix_state_lock(), then emit the netlink attribute after dropping the
lock.
This keeps the VFS data stable while the reply is being built. |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: clear trailing padding in build_polexpire()
build_expire() clears the trailing padding bytes of struct
xfrm_user_expire after setting the hard field via memset_after(),
but the analogous function build_polexpire() does not do this for
struct xfrm_user_polexpire.
The padding bytes after the __u8 hard field are left
uninitialized from the heap allocation, and are then sent to
userspace via netlink multicast to XFRMNLGRP_EXPIRE listeners,
leaking kernel heap memory contents.
Add the missing memset_after() call, matching build_expire(). |
| In the Linux kernel, the following vulnerability has been resolved:
batman-adv: hold claim backbone gateways by reference
batadv_bla_add_claim() can replace claim->backbone_gw and drop the old
gateway's last reference while readers still follow the pointer.
The netlink claim dump path dereferences claim->backbone_gw->orig and
takes claim->backbone_gw->crc_lock without pinning the underlying
backbone gateway. batadv_bla_check_claim() still has the same naked
pointer access pattern.
Reuse batadv_bla_claim_get_backbone_gw() in both readers so they operate
on a stable gateway reference until the read-side work is complete.
This keeps the dump and claim-check paths aligned with the lifetime
rules introduced for the other BLA claim readers. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gt: fix refcount underflow in intel_engine_park_heartbeat
A use-after-free / refcount underflow is possible when the heartbeat
worker and intel_engine_park_heartbeat() race to release the same
engine->heartbeat.systole request.
The heartbeat worker reads engine->heartbeat.systole and calls
i915_request_put() on it when the request is complete, but clears
the pointer in a separate, non-atomic step. Concurrently, a request
retirement on another CPU can drop the engine wakeref to zero, triggering
__engine_park() -> intel_engine_park_heartbeat(). If the heartbeat
timer is pending at that point, cancel_delayed_work() returns true and
intel_engine_park_heartbeat() reads the stale non-NULL systole pointer
and calls i915_request_put() on it again, causing a refcount underflow:
```
<4> [487.221889] Workqueue: i915-unordered engine_retire [i915]
<4> [487.222640] RIP: 0010:refcount_warn_saturate+0x68/0xb0
...
<4> [487.222707] Call Trace:
<4> [487.222711] <TASK>
<4> [487.222716] intel_engine_park_heartbeat.part.0+0x6f/0x80 [i915]
<4> [487.223115] intel_engine_park_heartbeat+0x25/0x40 [i915]
<4> [487.223566] __engine_park+0xb9/0x650 [i915]
<4> [487.223973] ____intel_wakeref_put_last+0x2e/0xb0 [i915]
<4> [487.224408] __intel_wakeref_put_last+0x72/0x90 [i915]
<4> [487.224797] intel_context_exit_engine+0x7c/0x80 [i915]
<4> [487.225238] intel_context_exit+0xf1/0x1b0 [i915]
<4> [487.225695] i915_request_retire.part.0+0x1b9/0x530 [i915]
<4> [487.226178] i915_request_retire+0x1c/0x40 [i915]
<4> [487.226625] engine_retire+0x122/0x180 [i915]
<4> [487.227037] process_one_work+0x239/0x760
<4> [487.227060] worker_thread+0x200/0x3f0
<4> [487.227068] ? __pfx_worker_thread+0x10/0x10
<4> [487.227075] kthread+0x10d/0x150
<4> [487.227083] ? __pfx_kthread+0x10/0x10
<4> [487.227092] ret_from_fork+0x3d4/0x480
<4> [487.227099] ? __pfx_kthread+0x10/0x10
<4> [487.227107] ret_from_fork_asm+0x1a/0x30
<4> [487.227141] </TASK>
```
Fix this by replacing the non-atomic pointer read + separate clear with
xchg() in both racing paths. xchg() is a single indivisible hardware
instruction that atomically reads the old pointer and writes NULL. This
guarantees only one of the two concurrent callers obtains the non-NULL
pointer and performs the put, the other gets NULL and skips it.
(cherry picked from commit 13238dc0ee4f9ab8dafa2cca7295736191ae2f42) |